Gearing



Aug. 13, 1929. c, RUF 1,724,518

GEARING Filed March 1928 I N VEN TOR- 6/119 Zia/21 zqgeneRuf PatentedAug. 13, 1 .929.

ra n GAGE COMPANY, INC., A CORPORATION OF NEW YORK.

Guanine.

Application filed. March 2, 1928. Serial No. 258,498.

This invention relates to a novel construction of compensating compoundgearing, whereby all lost motion and backlash between the teeth of theintermeshing gears,

5 or a gear and a rack is prevented; the device being particularlyadaptable to operating fine and delicate mechanisms, such as gear drivenindicating gauges, speedometers, time and recording instruments, orother devices requiring driving means for theindicating hand which shallhave no lost motion to cause any inaccuracy.

In the construction of dial indicators or gear driven gauges formeasuring purposes,

it has been found that there must not be any lost motion or backlash inthe train of gears which transmit movement from the contact plunger tothe indicating hand on the dial, and this has been accomplishedheretofore by the use of a spiral or hair springgso mounted as to exerta tension on one or more of the gears to bring one side of their teethinto a pressing or follow-up contact with the teeth of the gear or rackwhich it is to drive, but such a spring has many disadvantages, amongwhich is the difference in tension of such a spring according to theposition of the gearsjexerting a varying tension or pressure accordingas to how tight the spring is wound up, thus producing an instrumenthaving a jerky movement;

' further such a spring is very delicate, easily broken and gotten outoforder, and also adding many extra parts to the mechanism.

Also'in some of the devices which have been devised for this purpose,provision has been made to prevent lost motion between the operatingpinion on which the indicat ing hand is mounted, and the gear thatdrives it directly, but no provision has been made to prevent lostmotion between the actuating plunger, and the above mentioned gearthatdrives the pinion, so that the amount indicated on the dial may still bein accurate owing to the lost motion between the plunger and the firstgear in the train of gearing.

The object of the present invention is to produce a novel compound gearthat shall at all times and under all conditions prevent any and alllost mostion or backlash between it and any gear or rack into which itsteeth shall be meshed.

Another object of the invention is to provide such a gear that shall becheap, simple,

durable and contain few parts and require no adjustments of any kind,and be fully automatic in the compensation for wear in the teeth.

till another object being to provide a and combination of parts as willhereinafter be fully described and claimed, and illustrated in theaccompanying drawings which form a part hereof and in which like figuresof reference refer to corresponding parts in all of the views, and it isto be understood that slight changes may be made without departing fromthe spirit of the invention.

In the drawings Figure 1 shows a view of such a com pound gear, and itsrelation to a driving and driven gears.

Figure 2 shows a sectional view of the same, without the driven gear,and taken on the line BB of Figure 1.

Figure 3 shows a sectional view of the same, taken on the line AA ofFigure 1, and showing the compensating spring.

Figure 4 shows an end view of Figure 1. Figure 5 shows an enlargeddetail view, illustrating the action of the split or take-up two partgears.

Referring to the drawings, we provide a shaft. 10, which may berotatably mounted in any suitable manner in the device to which theinvention is to be adapted; and we also show a driving shaft 11,carrying a pinion 12; and a driven shaft 13 carrying a gear 14; but itis to be understood that in place of the gears 12 and 14, and the shafts11 and, 13, that racks may be used in either or both cases, or anydesirable form of gearing, and that. in fact the invention will apply inan equal manner to spur, spiral, bevel, or any other form of gearing,and with any desired number of teeth, and of any pitch, the object beingat all times and under all conditions to provide a full or expandingtooth, to mesh with that of the other gear or rack.

To accomplish this we have rigidly secured on the shaft 10, near one endthereof, by the key 15 a two-part gear 16 and 24; and on the other endof the same shaft 10, another twopart gear 17 and 20, by a key 18 orother suitable means.

The gear 17 is formed with a turned or machined hub 19, on which isfreely mounted the narrow faced gear 20, which is of the same size andtooth as the gear 17, and in fact forms a part thereof, only not beingsecured to the shaft.

Adjacent to this gear 20 and also freely mounted on the shaft 10, isplaced a disk 21, which is also formed with a turned hub 22, on the endof which is rigidly secured by a key 23 or other device, a narrow facedgear 24, of the same size and tooth as the gear 16, and forming a partof the same, but not secured to the shaft 10.

The gear 20, at a point near the periphery thereof has attacheed theretoa stud 25; and the disk 21 has a similar stud 26, attached to its side,said studs standing at right angles to and projecting from the sides ofthe gear and the disk, and being parallel to each other, and pointing inopposite directions.

Referring to' Figure 3 of the drawings, the hub 19 of the gear 17, isformed with a slot or saw-cut 27, within which by being staked orotherwise secured is a flat or leaf spring 28, which is formed withoppositely positioned hooked ends 29 and 30; the hook 29 engaging thestud 25 on the gear 20; and

I the hook 330 engaging the stud 26 on the disk Now in the assembly ofthe device, the gear 20 is moved one or more teeth in relation to thegear 17 and in a direction to place tension on the spring 28, and thetwo gears 17 and 20, forming the two-part gear are meshed with thepinion 14; and the gear 24 is then moved in relation to the gear 16, thesame number of teeth, but in the opposite direction, and then the gears24 and 16, making up the other two-part gear are meshed with thegear-l2.

It will thus be seen that the teeth of the gear '20, owing to theexertion of the spring 28 will have a desire to pass or become out ofline with the teeth of the gear 17 thus at all times completely fillingthe spaces of the teeth with which they are in mesh, as in this case thegear 14, thus preventing all lostmotion, backlash and noise between saidgears, and this same condition exists in regard to the gears 24 and 16,with respect to the pinion 12, only the pressure of the teeth are in theopposite direction.

This provides a self-contained compound gear unit, with compensatingmeans for preventing lost motion, backlash and noise, and comprises twogears, each made up of two parts; one part secured. to a shaft, and theother part loose, and all being provided with a novel device for keepingthe teeth on each of the two parts out of alinement with each other, andforming a two-part gear with an expanding tooth.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is:

1. A self-contained compound gear unit, comprising in combination with ashaft, of two gears, each rigidly secured upon said shaft in spacedrelation with each other, a hub formed on one of said gears, a gearmounted on said hub and having rotary movement thereon, a disk mountedon said shaft between said gears, a hub formed on said disk, a gearrigidly secured upon said hub in contact with the second gear, and meanscarried by said disk, the gear mounted on the hub of the first gear andsaid hub, for preventing lost motion or backlash be tween said gear unitand any toothed members it either drives or is driven by 2. A compoundgear unit, comprising in combination with a shaft, of a pair ofcompensating gears mounted on said shaft in spaced relation, each ofsaid compensating gears composed of two parts, the first part secured tosaid shaft, and the second part freely rotatable With respect to saidshaft, a disk rotatably mounted on said shaft between said gears, one ofsaid loose gears secured to said disk, a stud carried by the other loosegear, a similar stud carried by the disk, and a spring having its bodyportion secured to one of the gears secured to said shaft, and

its ends in engagement with said studs, exerting pressure on said studsin opposite directions from each other, to bring the teeth of said loosegears out of alinement with the corresponding teeth of the gears formingthe first parts thereof. 2

In testimony whereof I afiix my signature.

C. EUGENE RUF.

